Lennox 4 Series Installation Manual page 14

5.6. Piping Between Indoor and Outdoor Units
1. Ensure the liquid and gas stop valves marked A, B, C, D and E are closed if they have not been
connected to the indoor units.
2. Refer to Table 7 for the moments of torque for tightening screws.
3. Point the flare end of the copper pipe at the screw and tighten by hand.
4. Tighten using the appropriate torque wrench as shown in Table 7.
5. Use a pipe tube bender to bend the pipe. Ensure that the bend radius is not too small, otherwise
cracks may occur resulting in leakage.
6. Wrap the exposed refrigerant pipe and the joints with insulation and then tighten them with plastic
tape.
Table 7: Moments of Torque
Pipe Diameter (mm)
Φ6.35
Φ9.52
Φ12.70
Φ15.90
CAUTION
• During the connection of the indoor unit and the refrigerant pipe, do not apply too much force to
the joints of the indoor unit; as this may cause the capillary pipe or other pipes to crack and result
in leakage.
• The refrigerant pipe should be supported by brackets.
• If the piping connection size of outdoor unit does not match the piping connection size of indoor
unit, use the piping connection dimension of indoor unit. And use different-diameter joints at the
piping connection to connect the indoor unit.
CAUTION
• For the Multi Split Inverter, each pipe should be labeled with the indoor unit details for easy reference
and to avoid incorrect piping.
14
LENNOX MULTI SPLIT INVERTER
Thickness of Copper Tube (mm)
≥0.8 mm
≥0.8 mm
≥ 0.8 mm
≥1.0 mm
Outdoor Unit
Tightening Torque (N·m)
15 - 30
35 - 40
45 - 50
60 - 65
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